Alternator Problems???

[collegeoffroad]

1989 XJ Ltd.

Measures 12v at the battery(and on the gauge) and dips when i put on the brights, and heat. After giving it some gas, the voltage does not return to 12v and also never gets to the 14-15v that it probably should be running...

we just finished replacing the alternator and tested what we thought were the fusible links for shorts, however I"m not sure we even tested the right thing. So what I need to know is a few things...

1.) ANy ideas?
2.) Where are the fusible links? In the hanes manual, it shows a fuse box, whereas online here, I found the FSM and it shows fusible links...don't know which one to believe!

TIA for the help guys! :wave:

 

[Lunatic728]

check and or replace the ground to the body. It is on the rear drivers side of the head and connects to the body with a short cable. I would also check all the connections and make sure they are clean and good condiiton.

By the way the factory volt meter sucks, if I just turn on the fan (hi) it drops to just above the 12 or 13 mark. But if I turn on my brights, and any other light I can think of it just sits there and does not show a voltage drop or it is very slight.

Here is a link to a webpage that may help.

http://www.olypen.com/craigh/charge.htm

 

[MJR]

You have battery power at the alternator output lug? The smaller connector that plugs into the alternator you should have ignition switched power on one of the wires. If you have both then it's the alternator unless the engine ground wire (at the oil dipstick tube mounting) is not connected.

 

[collegeoffroad]

thanks for the help guys! The site was really usefull even after we figured out what was wrong. Turns out that the replacement alternator was bad as well. Put in a new one and everything's workin' great!

 

[fire325]

I'm in the process of doing this upgrade, and need some help on something. I'm probably doing a little overkill on using 2/0 welding cable, but, i've got it and need to use it, if i can.

Question is, i've got a 2/0 cable to run from the alternator to the power distribution center. I'm having trouble with the cable and ends being too large to fit in the back of the alternator. Would it be safe to use 2 guage or 4 guage for this, even if i still use the 2/0 for my negative and positive battery cables?

I'm doing the upgrade on this site http://www.olypen.com/craigh/charge.htm

My XJ is a '92 4.0 HO. I have the 100A fuse to use between the PDC and the alternator. I've taken the (2) 60A fuses out of the fuse box under the hood that controls the alt. Thanks for the help gang. Rocks!!

Member #579
Thanks
Darrell

 

[90Pioneer]

I'm in the process of doing this upgrade, and need some help on something. I'm probably doing a little overkill on using 2/0 welding cable, but, i've got it and need to use it, if i can.

Question is, i've got a 2/0 cable to run from the alternator to the power distribution center. I'm having trouble with the cable and ends being too large to fit in the back of the alternator. Would it be safe to use 2 guage or 4 guage for this, even if i still use the 2/0 for my negative and positive battery cables?

I'm doing the upgrade on this site http://www.olypen.com/craigh/charge.htm

My XJ is a '92 4.0 HO. I have the 100A fuse to use between the PDC and the alternator. I've taken the (2) 60A fuses out of the fuse box under the hood that controls the alt. Thanks for the help gang. Rocks!!

Member #579
Thanks
Darrell

I'm trying to use 2 gauge to do the same, and I've found that it's too big as well.

 

[fire325]

I think i may use a 100A circuit breaker instead of the 100A fuse. That way if i'm on the trail, i can just reset it.